Effective Reduction in Natural Enemy Catches in Pheromone Traps Intended for Monitoring Orthotomicus erosus (Coleoptera, Curculionidae)

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The authors present a manuscript seeking to address the problem of bycatch of beneficial predatory beetles in Mediterranean pine engraver (MPE) traps. The authors conclude that by covering the MPE traps in wire mesh there are “30 % fewer predatory beetles compared to the standard traps”, also “…up to four times fewer beetles of non-target species were captured in the modified traps than in the standard traps.” Although these statements demonstrate some effectiveness of the modified trap design, they seem a little contradictory or else unclear; was there a 30 % reduction (roughly a 1/3 reduction) or a reduction of 4 times? In other places as well, the authors choice of wording seems to obscure the intended meaning to some degree. A thorough review / editing of the English language and grammar is in order, and also a rephrasing of several key statements to make the meaning more clear. I have noted as many of these, as well as more minor editorial comments, below. However, my comments are not exhaustive and further editing is in order.

Further comments to authors:

 

-what chemicals were used in the MPE lure? Was this ersowit, or pheroprax, or something else? Do the authors know the chemicals in these lures? And how were they synthesized / sourced? I’m assuming they were purchased commercially; this should definitely be specified.

 

-line 24 of abstract, “…traps were deployed at the onset of a significant O. erosus outbreak in Croatia in 2018”…why isn’t this data included? It is not completely necessary, but the authors could offer an explanation of why it isn’t.

 

-line 49, omit the second “of bark beetles” in this line

 

-line 51, “beetle” instead of “beetles”

 

-line 52, “scenarios” instead of “scenario”, “have” instead of “had”

-line 61, do the authors mean two generations per year? This could be clarified.

 

-line 65, “the outbreak site”, which outbreak site? The one in the authors’ study? This could be clarified.

 

-line 66-67, “an unusually warm November and December” instead of “unusual warm November and December”

 

-line 71 “because of” instead of “by”

 

-line 71-73, for an alternate wording of this sentence, I suggest “…may be factors that favorably affect the pest insect.” instead of “…may be favorable for the pest insect.”

 

-line 74, recommend “…several generations above the usual number per year…” as an alternate wording.

 

-line 76, “years” not “year”

 

-line 77 “purposes” not “purpose”

 

-line 80, omit “rather”

 

-lines 85-86, recommend “…Theysohn traps have been shown to be an optimal solution.” As an alternate wording.

 

-line 87, omit “also”

 

-line 91, maybe “ipsenol, ipsdienol…” not “ipsenol i ipsdienol”

 

-line 97,recommend “even” instead of “no matter”

 

-line 98, insert “the” before “number”

 

-lines 102 and 103, recommend “Predatory species remained trapped and fed off the catches…” as an alternate working.

 

-line 124, recommend “…Marjan is ca. 300 ha. in size with forest making up approximately two-thirds of it.” as an alternatve wording.

 

-line 126, insert “and” before “today”

 

-the meaning of lines 129-139 is very unclear. An open-air laboratory? I’m not sure I understand what the authors are trying to say. Are they referring to their field study? This should be clarified.

 

-line 142 “Theysohn” not “Thesohn’

 

-line 146, I recommend this sentence be corrected to “…7 to (insert space) 14 days (9 days in average).”

 

-line 152 “…after 2 weeks maximum.” Not “…maximum after 2 weeks.”

 

-line 187, recommend “…show the collapse of the outbreak very clearly (Figure 3)” as an alternate wording,

 

-lines 241-244, the meaning of this sentence is unclear. Is the decrease in predatory beetle capture 1 %, or is it 30 %? I think this is a grammatical error / obscure meaning which I feel the authors should try to address by expressing their thoughts with more clarity.

 

-line 257, “long time-frames” not “longtime frames”

 

-line 259, I suggest “undone” instead of “prevented”

 

-line 260, insert “captured” after “predators”

 

-line 265, by stating “The number of MPE catches in 2022 is negligible comparing with (I recommend “compared to”) catches from previous years and represents the entry of the bark beetle into latency.” Are the authors jumping to conclusions? There could be other explanations for the MPE population crash…

 

-line 268 “numbers” not “number”

 

-line 270 “resulted” not “resulting”

 

-line 276-277, the meaning of the sentence beginning with “The results indicate…” is unclear, maybe this should be reworded?

 

-line 282 “is” instead of “are”

 

-line 304 “is” instead of "was”

 

-line 316 “attracts” instead of “attract”

 

-line 317 “which” instead of “and”

 

-line 329 remove the quotation mark, likewise on line 371

 

-line 425 “differences” not “diffrences”

Comments on the Quality of English Language

The meaning of several of the authors statements seems obscured by unclear grammar / English language; I have noted as many of these as possible in my comments to the authors, but I feel further thorough editing for English language is in order.

Author Response

The authors present a manuscript seeking to address the problem of bycatch of beneficial predatory beetles in Mediterranean pine engraver (MPE) traps. The authors conclude that by covering the MPE traps in wire mesh there are “30 % fewer predatory beetles compared to the standard traps”, also “…up to four times fewer beetles of non-target species were captured in the modified traps than in the standard traps.” Although these statements demonstrate some effectiveness of the modified trap design, they seem a little contradictory or else unclear; was there a 30 % reduction (roughly a 1/3 reduction) or a reduction of 4 times? In other places as well, the authors choice of wording seems to obscure the intended meaning to some degree. A thorough review / editing of the English language and grammar is in order, and also a rephrasing of several key statements to make the meaning more clear. I have noted as many of these, as well as more minor editorial comments, below. However, my comments are not exhaustive and further editing is in order.

Further comments to authors:

 

-what chemicals were used in the MPE lure? Was this ersowit, or pheroprax, or something else? Do the authors know the chemicals in these lures? And how were they synthesized / sourced? I’m assuming they were purchased commercially; this should definitely be specified.

 It's about pheromones that were purchased on the market whose composition is known and published. t is explained in the text that it is about Erosowit.

-line 24 of abstract, “…traps were deployed at the onset of a significant O. erosus outbreak in Croatia in 2018”…why isn’t this data included? It is not completely necessary, but the authors could offer an explanation of why it isn’t.

 It's about a large amount of data that cannot be adequately processed in a small space such as an article. Additionally, the pheromones were tested in the first years and were modified, as were the number and position of traps. We considered that a quality comparison of the catch was not possible from 2018, only from 2021 onward.

-line 49, omit the second “of bark beetles” in this line

 Done

-line 51, “beetle” instead of “beetles”

 Done

-line 52, “scenarios” instead of “scenario”, “have” instead of “had”

Done

-line 61, do the authors mean two generations per year? This could be clarified.

 We add „per year“

-line 65, “the outbreak site”, which outbreak site? The one in the authors’ study? This could be clarified.

 We add „Marjan (Split, Croatia)

-line 66-67, “an unusually warm November and December” instead of “unusual warm November and December”

 Done

-line 71 “because of” instead of “by”

 Done

-line 71-73, for an alternate wording of this sentence, I suggest “…may be factors that favorably affect the pest insect.” instead of “…may be favorable for the pest insect.”

  Thank you for this suggestion, we made the change.

-line 74, recommend “…several generations above the usual number per year…” as an alternate wording.

 Thank you for this suggestion, we made the change.

-line 76, “years” not “year”

 Done

-line 77 “purposes” not “purpose”

 Done

-line 80, omit “rather”

 We delete it

-lines 85-86, recommend “…Theysohn traps have been shown to be an optimal solution.” As an alternate wording.

  Thank you for this suggestion, we made the change.

-line 87, omit “also”

 Done

-line 91, maybe “ipsenol, ipsdienol…” not “ipsenol i ipsdienol”

 Done

-line 97,recommend “even” instead of “no matter”

 Done

-line 98, insert “the” before “number”

 Done

-lines 102 and 103, recommend “Predatory species remained trapped and fed off the catches…” as an alternate working.

 Done

-line 124, recommend “…Marjan is ca. 300 ha. in size with forest making up approximately two-thirds of it.” as an alternatve wording.

   Thank you for this suggestion, we made the change.

-line 126, insert “and” before “today”

 Done

-the meaning of lines 129-139 is very unclear. An open-air laboratory? I’m not sure I understand what the authors are trying to say. Are they referring to their field study? This should be clarified.

   Thank you for this suggestion, we made the change.

-line 142 “Theysohn” not “Thesohn’

 Done

-line 146, I recommend this sentence be corrected to “…7 to (insert space) 14 days (9 days in average).”

    Thank you for this suggestion, we made the change.

-line 152 “…after 2 weeks maximum.” Not “…maximum after 2 weeks.”

 Done

-line 187, recommend “…show the collapse of the outbreak very clearly (Figure 3)” as an alternate wording,

Done

 -lines 241-244, the meaning of this sentence is unclear. Is the decrease in predatory beetle capture 1 %, or is it 30 %? I think this is a grammatical error / obscure meaning which I feel the authors should try to address by expressing their thoughts with more clarity.

 We corrected it.

-line 257, “long time-frames” not “longtime frames”

 Corrected

-line 259, I suggest “undone” instead of “prevented”

 Accept that. Done

-line 260, insert “captured” after “predators”

  Accept that. Done

-line 265, by stating “The number of MPE catches in 2022 is negligible comparing with (I recommend “compared to”) catches from previous years and represents the entry of the bark beetle into latency.” Are the authors jumping to conclusions? There could be other explanations for the MPE population crash…

 That is a fact; today it is known 2 years after the outbreak. We added (Pernek unpublished).

-line 268 “numbers” not “number”

 Done

-line 270 “resulted” not “resulting”

 Done

-line 276-277, the meaning of the sentence beginning with “The results indicate…” is unclear, maybe this should be reworded?

 We delete the sentence in order to avoid misunderstandings.

-line 282 “is” instead of “are”

Done

-line 304 “is” instead of "was”

 Done

-line 316 “attracts” instead of “attract”

 Done

-line 317 “which” instead of “and”

Done

 -line 329 remove the quotation mark, likewise on line 371

 Done

-line 425 “differences” not “diffrences”

Done

 

Comments on the Quality of English Language

The meaning of several of the authors statements seems obscured by unclear grammar / English language; I have noted as many of these as possible in my comments to the authors, but I feel further thorough editing for English language is in order.

We send it to profesional proofreading.

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript “Effective reduction of natural enemy catches in pheromone traps intended for monitoring Orthotomicus erosus (Coleoptera, Curculionidae)” (authors Milan Pernek, Tomislav Milas, Marta Kovač, Nikola Lacković, Milan Koren, Boris Hrašovec) continues the theme discussed in the paper Pernek M., Lacković N., Lukić I., Zorić N., Matošević D. Outbreak of Orthotomicus erosus (Coleoptera, Curculionidae) on Aleppo Pine in the Mediterranean Region in Croatia. South-east Eur. For. 2019, 10 (1), 19-27. doi: 10.15177/seefor.19-05. The new MS aims to verify the effectiveness of the modernization of pheromone traps designed for monitoring the Mediterranean pine engraver (MPE), Orthotomicus erosus. The purpose of the trap modernization was to try to reduce the captures of non-target entomofauna by pheromone traps, primarily predatory beetles. Although the MS provides 3-year MPE monitoring data, the comparison of the effectiveness of standard (i.e. original) and upgraded traps, which were placed by 10 pairs, was carried out only for a single year. The results are presented in several tables and figures, and first of all, the data obtained indicate a very large range of variation in beetle trapping with both standard and modified traps (Fig. 4). The authors write: “Although the pairs of standard and modified traps were placed close to each other and under similar conditions, the number of beetles captured was different (Figure 4)”, and this is indeed the case, if it turned out that in half of the pairs of traps more beetles were caught by standard, and in other half – by upgraded traps… Actually, this state of art in working with traps is very common, which is faced by almost every researcher who has been professionally engaged in this work. Accordingly, tests of traps, including equipped with pheromones, they usually try to carry out for several seasons, and conditions are preferable when the number of the monitoring object varies as widely as possible. In order to prove the validity of the differences in one-year catches of beetles with standard and upgraded traps, the authors of the MS applied the permutation paired t-test, and to assess the significance of the differences between the ratios of different beetle species in catches by both trap designs, a two-sample test for equality of proportions with a continuity correction was used. At the same time, it should be borne in mind that the single-year results of catching MPE and other beetle species may well lead to incorrect conclusions, especially if we consider that the MPE population density in the year when paired trap tests were carried out turned out to be significantly lower than in the previous two seasons, when monitoring was carried out only using standard trap designs. So, when decided to publish this MS, then the conclusion “our results have shown that the average number of O. erosus captured in the standard traps was statistically significantly higher than the average number captured in the modified traps” should be reformulated so that the assumption meaning prevails with a reservation on the need for further field testing. And yet, some places in the MS are written incomprehensibly, for example, this one: “The difference in the number of MPE in the standard trap and modified trap #7 is less extreme. However, the trend in the number of MPE in modified trap #7 does not match the trend in the number of MPE in standard trap #7. It is possible that this can be explained by the placement of modified trap #7.”

Author Response

The manuscript “Effective reduction of natural enemy catches in pheromone traps intended for monitoring Orthotomicus erosus (Coleoptera, Curculionidae)” (authors Milan Pernek, Tomislav Milas, Marta Kovač, Nikola Lacković, Milan Koren, Boris Hrašovec) continues the theme discussed in the paper Pernek M., Lacković N., Lukić I., Zorić N., Matošević D. Outbreak of Orthotomicus erosus (Coleoptera, Curculionidae) on Aleppo Pine in the Mediterranean Region in Croatia. South-east Eur. For. 2019, 10 (1), 19-27. doi: 10.15177/seefor.19-05. The new MS aims to verify the effectiveness of the modernization of pheromone traps designed for monitoring the Mediterranean pine engraver (MPE), Orthotomicus erosus. The purpose of the trap modernization was to try to reduce the captures of non-target entomofauna by pheromone traps, primarily predatory beetles. Although the MS provides 3-year MPE monitoring data, the comparison of the effectiveness of standard (i.e. original) and upgraded traps, which were placed by 10 pairs, was carried out only for a single year. The results are presented in several tables and figures, and first of all, the data obtained indicate a very large range of variation in beetle trapping with both standard and modified traps (Fig. 4). The authors write: “Although the pairs of standard and modified traps were placed close to each other and under similar conditions, the number of beetles captured was different (Figure 4)”, and this is indeed the case, if it turned out that in half of the pairs of traps more beetles were caught by standard, and in other half – by upgraded traps… Actually, this state of art in working with traps is very common, which is faced by almost every researcher who has been professionally engaged in this work. Accordingly, tests of traps, including equipped with pheromones, they usually try to carry out for several seasons, and conditions are preferable when the number of the monitoring object varies as widely as possible. In order to prove the validity of the differences in one-year catches of beetles with standard and upgraded traps, the authors of the MS applied the permutation paired t-test, and to assess the significance of the differences between the ratios of different beetle species in catches by both trap designs, a two-sample test for equality of proportions with a continuity correction was used. At the same time, it should be borne in mind that the single-year results of catching MPE and other beetle species may well lead to incorrect conclusions, especially if we consider that the MPE population density in the year when paired trap tests were carried out turned out to be significantly lower than in the previous two seasons, when monitoring was carried out only using standard trap designs. So, when decided to publish this MS, then the conclusion “our results have shown that the average number of O. erosus captured in the standard traps was statistically significantly higher than the average number captured in the modified traps” should be reformulated so that the assumption meaning prevails with a reservation on the need for further field testing. And yet, some places in the MS are written incomprehensibly, for example, this one: “The difference in the number of MPE in the standard trap and modified trap #7 is less extreme. However, the trend in the number of MPE in modified trap #7 does not match the trend in the number of MPE in standard trap #7. It is possible that this can be explained by the placement of modified trap #7.”

The research on selectivity began in the late outbreak, which is the main reason why studies were not conducted for several years. The number of bark beetles significantly decreased, and the results would have been even more difficult to interpret.

We agree with the reviewer; however, we believe that the results are important even in this form because they help the praxis in selecting pheromone traps. We also agree that further field tests will be necessary, and this work would serve as a foundation for further analysis. Therefore, we have added in the Conclusion that additional testing is needed.

 

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have followed up on all of my editorial points, and answered my questions appropriately.

I just have a few outstanding editorial concerns; once these are fixed, I feel the paper can be published.

-lines 86 and 91, is it Pheroprax or Pheropraxa? I think the former; this should be corrected.

-line 127, I suggest "...covered with holm oak and manna ash forest..." not "...covered with holm oak with manna ash forest..."

-line 139, I suggest replacing "needed" with "was"

-on line 140, maybe the source of the steel mesh? Was it purchased or made from scratch?

-Figure 7, the legend to the right of the figure,

Trap

a Modified

a Standard

 In my black-and-white and grey manuscript copy, a Modified and a Standard don't look any different from each other...I know the figure shows the percentage of beetle species caught in these 2 types of traps, but I can't tell which is which; is one bold and the other isn't? Maybe just a little reformatting to make the table more clear would be good.

-lines 268-270, the sentence beginning with "In the extreme case,..." is slightly grammatically hard to follow; maybe a rephrasing to "In the extreme case, the number of predators caught and removed from the population is so high that, considering their potential food consumption, we may cause more harm that good." 

Comments on the Quality of English Language

Once the minor editorial points that I raise in my comments to authors are addressed, I feel the quality of English language of the manuscript is good enough to publish.

Author Response

-lines 86 and 91, is it Pheroprax or Pheropraxa? I think the former; this should be corrected.

Done. 

-line 127, I suggest "...covered with holm oak and manna ash forest..." not "...covered with holm oak with manna ash forest..."

Done.

-line 139, I suggest replacing "needed" with "was"

Done.

-on line 140, maybe the source of the steel mesh? Was it purchased or made from scratch?

It was made from scratch. We added that in the sentence.

-Figure 7, the legend to the right of the figure,

Trap

a Modified

a Standard

 In my black-and-white and grey manuscript copy, a Modified and a Standard don't look any different from each other...I know the figure shows the percentage of beetle species caught in these 2 types of traps, but I can't tell which is which; is one bold and the other isn't? Maybe just a little reformatting to make the table more clear would be good.

In a new version of manuscript modified traps are coloured pink and standard traps are coloured blue,. We believe it will be published like that so it would be different from each other. 

-lines 268-270, the sentence beginning with "In the extreme case,..." is slightly grammatically hard to follow; maybe a rephrasing to "In the extreme case, the number of predators caught and removed from the population is so high that, considering their potential food consumption, we may cause more harm that good." 

Done.